Mathematically, it means that a line segment is divided into AC and BC, and the ratio of long segment AC to whole segment AB is 0.6 18: 1, that is, the long segment is 0.6 18 of the whole segment.
It can also mean that there is a certain mathematical proportional relationship between the parts of things, that is, the whole is divided into two parts, and the ratio of the larger part to the smaller part is equal to the ratio of the whole to the larger part, and the ratio is 1: 0.6 18.